In recent years, a cell phone is structured as an optical device on which an optical unit for photographing is mounted. In the optical unit, in order to restrain disturbance of a photographed image due to a shake of a user's hand, a structure has been proposed in which an optical module is swung to correct the shake. In order to perform the shake correction, the optical module is required to be swingably supported by a fixed body.
Therefore, a structure has been proposed in which an optical module is swingably supported by a pivot provided on a rear side in an optical axis direction of the optical module and the optical module is swung with the pivot as a swing center so as to correct a shake of the optical unit (see Patent Literatures 1 and 2).
However, in a case that an optical module is structured to swing with its rear side in an optical axis direction as a swing center, a displacement amount of the optical module is small on the rear side in the optical axis direction, but a displacement amount of the optical module is large on the front side in the optical axis direction. Therefore, a sufficient space is required to secure in a direction perpendicular to the optical axis direction around the optical module and thus, a size of the optical unit in the direction perpendicular to the optical axis direction becomes large.
On the other hand, a structure has been proposed that an optical module is swingably supported at a midway position in the optical axis direction of the optical module. According to this structure, a displacement amount of the optical module on the front side in the optical axis direction can be reduced (see Patent Literature 3). Further, in the optical unit described in Patent Literature 3, a structured has been proposed in which a movable module is structured so that a weight (counter weight) is provided on a rear side end part in an optical axis direction of an optical module (first movable part) and a mechanical resonance is restrained by setting a gravity center position of the movable module close to its swing center from a gravity center position of the optical module.